Recently, flexible display technology is mainly used in small and medium size products. In general, an LTPS-TFT back plane is used, where a low temperature poly-silicon (LTPS), which is crystallized by excimer laser annealing (ELA), serves as a channel layer of a thin film transistor (TFT). The electrical parameters (e.g., threshold voltage, subthreshold swing, mobility, etc.) of the TFT are strongly associated with a grain boundary density in the channel. To make an array substrate having good electrical uniformity, the LTPS film is required to have a very uniform grain size.
An LTPS film is constituted by many silicon grains, which inevitably have grain boundaries. Since an atomic binding force at a crystalline interface of the LTPS thin film is weak, an inter-granular fracture/deformation occurs at the grain boundary under a bending stress, so that electrical characteristics of the TFT are deteriorated and the device even fails.
Accordingly, it is necessary to provide a flexible organic light emitting diode display and manufacturing method thereof to solve the technical problems in the prior art.